Fig. 2

Ag NPs: (a) Experimental spectra (b) variation of the absorption bandwidth (FWHM) with NP size. c TEM sample for the 22.4-nm Ag NPs at minimum absorption bandwidth in b. d Theoretical curves computed from Eq. 3
Ag NPs: (a) Experimental spectra (b) variation of the absorption bandwidth (FWHM) with NP size. c TEM sample for the 22.4-nm Ag NPs at minimum absorption bandwidth in b. d Theoretical curves computed from Eq. 3